<?php

// vim: set et ts=4 sw=4 fdm=marker:
// +----------------------------------------------------------------------+
// | PHP versions 4 and 5                                                 |
// +----------------------------------------------------------------------+
// | Copyright (c) 1998-2006 Manuel Lemos, Tomas V.V.Cox,                 |
// | Stig. S. Bakken, Lukas Smith                                         |
// | All rights reserved.                                                 |
// +----------------------------------------------------------------------+
// | MDB2 is a merge of PEAR DB and Metabases that provides a unified DB  |
// | API as well as database abstraction for PHP applications.            |
// | This LICENSE is in the BSD license style.                            |
// |                                                                      |
// | Redistribution and use in source and binary forms, with or without   |
// | modification, are permitted provided that the following conditions   |
// | are met:                                                             |
// |                                                                      |
// | Redistributions of source code must retain the above copyright       |
// | notice, this list of conditions and the following disclaimer.        |
// |                                                                      |
// | Redistributions in binary form must reproduce the above copyright    |
// | notice, this list of conditions and the following disclaimer in the  |
// | documentation and/or other materials provided with the distribution. |
// |                                                                      |
// | Neither the name of Manuel Lemos, Tomas V.V.Cox, Stig. S. Bakken,    |
// | Lukas Smith nor the names of his contributors may be used to endorse |
// | or promote products derived from this software without specific prior|
// | written permission.                                                  |
// |                                                                      |
// | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS  |
// | "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT    |
// | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS    |
// | FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE      |
// | REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,          |
// | INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
// | BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS|
// |  OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED  |
// | AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT          |
// | LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY|
// | WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE          |
// | POSSIBILITY OF SUCH DAMAGE.                                          |
// +----------------------------------------------------------------------+
// | Author: Lukas Smith <smith@pooteeweet.org>                           |
// +----------------------------------------------------------------------+
//
// $Id: mysql.php,v 1.170 2006/10/31 18:46:43 lsmith Exp $
//

/**
 * MDB2 MySQL driver
 *
 * @package MDB2
 * @category Database
 * @author  Lukas Smith <smith@pooteeweet.org>
 */
//require "Class/Lib/MDB2/DataType/";
class MDB2_Driver_mysql extends MDB2_Driver_Common
{
	// {{{ properties
	var $string_quoting = array('start' => "'", 'end' => "'", 'escape' => '\\', 'escape_pattern' => '\\');

	var $identifier_quoting = array('start' => '`', 'end' => '`', 'escape' => '`');

	var $sql_comments = array(
	array('start' => '-- ', 'end' => "\n", 'escape' => false),
	array('start' => '#', 'end' => "\n", 'escape' => false),
	array('start' => '/*', 'end' => '*/', 'escape' => false),
	);

	var $start_transaction = false;

	var $varchar_max_length = 255;
	// }}}
	// {{{ constructor

	/**
	 * Constructor
	 */
	function __construct()
	{
		parent::__construct();

		$this->phptype = 'mysql';
		$this->dbsyntax = 'mysql';

		$this->supported['sequences'] = 'emulated';
		$this->supported['indexes'] = true;
		$this->supported['affected_rows'] = true;
		$this->supported['transactions'] = false;
		$this->supported['savepoints'] = false;
		$this->supported['summary_functions'] = true;
		$this->supported['order_by_text'] = true;
		$this->supported['current_id'] = 'emulated';
		$this->supported['limit_queries'] = true;
		$this->supported['LOBs'] = true;
		$this->supported['replace'] = true;
		$this->supported['sub_selects'] = 'emulated';
		$this->supported['auto_increment'] = true;
		$this->supported['primary_key'] = true;
		$this->supported['result_introspection'] = true;
		$this->supported['prepared_statements'] = 'emulated';
		$this->supported['identifier_quoting'] = true;
		$this->supported['pattern_escaping'] = true;
		$this->supported['new_link'] = true;

		$this->options['default_table_type'] = '';
	}

	// }}}
	// {{{ errorInfo()

	/**
	 * This method is used to collect information about an error
	 *
	 * @param integer $error
	 * @return array
	 * @access public
	 */
	function errorInfo($error = null)
	{
		if ($this->connection) {
			$native_code = @mysql_errno($this->connection);
			$native_msg  = @mysql_error($this->connection);
		} else {
			$native_code = @mysql_errno();
			$native_msg  = @mysql_error();
		}
		if (is_null($error)) {
			static $ecode_map;
			if (empty($ecode_map)) {
				$ecode_map = array(
				1004 => MDB2_ERROR_CANNOT_CREATE,
				1005 => MDB2_ERROR_CANNOT_CREATE,
				1006 => MDB2_ERROR_CANNOT_CREATE,
				1007 => MDB2_ERROR_ALREADY_EXISTS,
				1008 => MDB2_ERROR_CANNOT_DROP,
				1022 => MDB2_ERROR_ALREADY_EXISTS,
				1044 => MDB2_ERROR_ACCESS_VIOLATION,
				1046 => MDB2_ERROR_NODBSELECTED,
				1048 => MDB2_ERROR_CONSTRAINT,
				1049 => MDB2_ERROR_NOSUCHDB,
				1050 => MDB2_ERROR_ALREADY_EXISTS,
				1051 => MDB2_ERROR_NOSUCHTABLE,
				1054 => MDB2_ERROR_NOSUCHFIELD,
				1061 => MDB2_ERROR_ALREADY_EXISTS,
				1062 => MDB2_ERROR_ALREADY_EXISTS,
				1064 => MDB2_ERROR_SYNTAX,
				1091 => MDB2_ERROR_NOT_FOUND,
				1100 => MDB2_ERROR_NOT_LOCKED,
				1136 => MDB2_ERROR_VALUE_COUNT_ON_ROW,
				1142 => MDB2_ERROR_ACCESS_VIOLATION,
				1146 => MDB2_ERROR_NOSUCHTABLE,
				1216 => MDB2_ERROR_CONSTRAINT,
				1217 => MDB2_ERROR_CONSTRAINT,
				);
			}
			if ($this->options['portability'] & MDB2_PORTABILITY_ERRORS) {
				$ecode_map[1022] = MDB2_ERROR_CONSTRAINT;
				$ecode_map[1048] = MDB2_ERROR_CONSTRAINT_NOT_NULL;
				$ecode_map[1062] = MDB2_ERROR_CONSTRAINT;
			} else {
				// Doing this in case mode changes during runtime.
				$ecode_map[1022] = MDB2_ERROR_ALREADY_EXISTS;
				$ecode_map[1048] = MDB2_ERROR_CONSTRAINT;
				$ecode_map[1062] = MDB2_ERROR_ALREADY_EXISTS;
			}
			if (isset($ecode_map[$native_code])) {
				$error = $ecode_map[$native_code];
			}
		}
		return array($error, $native_code, $native_msg);
	}

	// }}}
	// {{{ escape()

	/**
	 * Quotes a string so it can be safely used in a query. It will quote
	 * the text so it can safely be used within a query.
	 *
	 * @param   string  the input string to quote
	 * @param   bool    escape wildcards
	 *
	 * @return  string  quoted string
	 *
	 * @access  public
	 */
	function escape($text, $escape_wildcards = false)
	{
		if ($escape_wildcards) {
			$text = $this->escapePattern($text);
		}
		$connection = $this->getConnection();
		if (PEAR::isError($connection)) {
			return $connection;
		}
		$text = @mysql_real_escape_string($text, $connection);
		return $text;
	}

	// }}}
	// {{{

	/**
	 * Start a transaction or set a savepoint.
	 *
	 * @param   string  name of a savepoint to set
	 * @return  mixed   MDB2_OK on success, a MDB2 error on failure
	 *
	 * @access  public
	 */
	function beginTransaction($savepoint = null)
	{
		$this->debug('Starting transaction/savepoint', __FUNCTION__, array('is_manip' => true, 'savepoint' => $savepoint));
		if (!is_null($savepoint)) {
			if (!$this->supports('savepoints')) {
				return $this->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
                    'savepoints are not supported', __FUNCTION__);
			}
			if (!$this->in_transaction) {
				return $this->raiseError(MDB2_ERROR_INVALID, null, null,
                    'savepoint cannot be released when changes are auto committed', __FUNCTION__);
			}
			$query = 'SAVEPOINT '.$savepoint;
			return $this->_doQuery($query, true);
		} elseif ($this->in_transaction) {
			return MDB2_OK;  //nothing to do
		}
		if (!$this->destructor_registered && $this->opened_persistent) {
			$this->destructor_registered = true;
			register_shutdown_function('MDB2_closeOpenTransactions');
		}
		$query = $this->start_transaction ? 'START TRANSACTION' : 'SET AUTOCOMMIT = 1';
		$result =& $this->_doQuery($query, true);
		if (PEAR::isError($result)) {
			return $result;
		}
		$this->in_transaction = true;
		return MDB2_OK;
	}

	// }}}
	// {{{ commit()

	/**
	 * Commit the database changes done during a transaction that is in
	 * progress or release a savepoint. This function may only be called when
	 * auto-committing is disabled, otherwise it will fail. Therefore, a new
	 * transaction is implicitly started after committing the pending changes.
	 *
	 * @param   string  name of a savepoint to release
	 * @return  mixed   MDB2_OK on success, a MDB2 error on failure
	 *
	 * @access  public
	 */
	function commit($savepoint = null)
	{
		$this->debug('Committing transaction/savepoint', __FUNCTION__, array('is_manip' => true, 'savepoint' => $savepoint));
		if (!$this->in_transaction) {
			return $this->raiseError(MDB2_ERROR_INVALID, null, null,
                'commit/release savepoint cannot be done changes are auto committed', __FUNCTION__);
		}
		if (!is_null($savepoint)) {
			if (!$this->supports('savepoints')) {
				return $this->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
                    'savepoints are not supported', __FUNCTION__);
			}
			$server_info = $this->getServerVersion();
			if (version_compare($server_info['major'].'.'.$server_info['minor'].'.'.$server_info['patch'], '5.0.3', '<')) {
				return MDB2_OK;
			}
			$query = 'RELEASE SAVEPOINT '.$savepoint;
			return $this->_doQuery($query, true);
		}

		if (!$this->supports('transactions')) {
			return $this->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
                'transactions are not supported', __FUNCTION__);
		}

		$result =& $this->_doQuery('COMMIT', true);
		if (PEAR::isError($result)) {
			return $result;
		}
		if (!$this->start_transaction) {
			$query = 'SET AUTOCOMMIT = 0';
			$result =& $this->_doQuery($query, true);
			if (PEAR::isError($result)) {
				return $result;
			}
		}
		$this->in_transaction = false;
		return MDB2_OK;
	}

	// }}}
	// {{{ rollback()

	/**
	 * Cancel any database changes done during a transaction or since a specific
	 * savepoint that is in progress. This function may only be called when
	 * auto-committing is disabled, otherwise it will fail. Therefore, a new
	 * transaction is implicitly started after canceling the pending changes.
	 *
	 * @param   string  name of a savepoint to rollback to
	 * @return  mixed   MDB2_OK on success, a MDB2 error on failure
	 *
	 * @access  public
	 */
	function rollback($savepoint = null)
	{
		$this->debug('Rolling back transaction/savepoint', __FUNCTION__, array('is_manip' => true, 'savepoint' => $savepoint));
		if (!$this->in_transaction) {
			return $this->raiseError(MDB2_ERROR_INVALID, null, null,
                'rollback cannot be done changes are auto committed', __FUNCTION__);
		}
		if (!is_null($savepoint)) {
			if (!$this->supports('savepoints')) {
				return $this->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
                    'savepoints are not supported', __FUNCTION__);
			}
			$query = 'ROLLBACK TO SAVEPOINT '.$savepoint;
			return $this->_doQuery($query, true);
		}

		$query = 'ROLLBACK';
		$result =& $this->_doQuery($query, true);
		if (PEAR::isError($result)) {
			return $result;
		}
		if (!$this->start_transaction) {
			$query = 'SET AUTOCOMMIT = 0';
			$result =& $this->_doQuery($query, true);
			if (PEAR::isError($result)) {
				return $result;
			}
		}
		$this->in_transaction = false;
		return MDB2_OK;
	}

	// }}}
	// {{{ function setTransactionIsolation()

	/**
	 * Set the transacton isolation level.
	 *
	 * @param   string  standard isolation level
	 *                  READ UNCOMMITTED (allows dirty reads)
	 *                  READ COMMITTED (prevents dirty reads)
	 *                  REPEATABLE READ (prevents nonrepeatable reads)
	 *                  SERIALIZABLE (prevents phantom reads)
	 * @return  mixed   MDB2_OK on success, a MDB2 error on failure
	 *
	 * @access  public
	 * @since   2.1.1
	 */
	function setTransactionIsolation($isolation)
	{
		$this->debug('Setting transaction isolation level', __FUNCTION__, array('is_manip' => true));
		if (!$this->supports('transactions')) {
			return $this->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
                'transactions are not supported', __FUNCTION__);
		}
		switch ($isolation) {
			case 'READ UNCOMMITTED':
			case 'READ COMMITTED':
			case 'REPEATABLE READ':
			case 'SERIALIZABLE':
				break;
			default:
				return $this->raiseError(MDB2_ERROR_UNSUPPORTED, null, null,
                'isolation level is not supported: '.$isolation, __FUNCTION__);
		}

		$query = "SET SESSION TRANSACTION ISOLATION LEVEL $isolation";
		return $this->_doQuery($query, true);
	}

	// }}}
	// {{{ connect()

	/**
	 * Connect to the database
	 *
	 * @return true on success, MDB2 Error Object on failure
	 */
	function connect()
	{
		if (is_resource($this->connection)) {
			if (count(array_diff($this->connected_dsn, $this->dsn)) == 0
			&& $this->opened_persistent == $this->options['persistent']
			) {
				return MDB2_OK;
			}
			$this->disconnect(false);
		}

		if (!PEAR::loadExtension($this->phptype)) {
			return $this->raiseError(MDB2_ERROR_NOT_FOUND, null, null,
                'extension '.$this->phptype.' is not compiled into PHP', __FUNCTION__);
		}

		$params = array();
		if ($this->dsn['protocol'] && $this->dsn['protocol'] == 'unix') {
			$params[0] = ':' . $this->dsn['socket'];
		} else {
			$params[0] = $this->dsn['hostspec'] ? $this->dsn['hostspec']
			: 'localhost';
			if ($this->dsn['port']) {
				$params[0].= ':' . $this->dsn['port'];
			}
		}
		$params[] = $this->dsn['username'] ? $this->dsn['username'] : null;
		$params[] = $this->dsn['password'] ? $this->dsn['password'] : null;
		if (!$this->options['persistent']) {
			if (isset($this->dsn['new_link'])
			&& ($this->dsn['new_link'] == 'true' || $this->dsn['new_link'] === true)
			) {
				$params[] = true;
			} else {
				$params[] = false;
			}
		}
		if (version_compare(phpversion(), '4.3.0', '>=')) {
			$params[] = isset($this->dsn['client_flags'])
			? $this->dsn['client_flags'] : null;
		}
		$connect_function = $this->options['persistent'] ? 'mysql_pconnect' : 'mysql_connect';

		$connection = @call_user_func_array($connect_function, $params);
		if (!$connection) {
			if (($err = @mysql_error()) != '') {
				return $this->raiseError(MDB2_ERROR_CONNECT_FAILED, null, null,
				$err, __FUNCTION__);
			} else {
				return $this->raiseError(MDB2_ERROR_CONNECT_FAILED, null, null,
                    'unable to establish a connection', __FUNCTION__);
			}
		}

		if (!empty($this->dsn['charset'])) {
			$result = $this->setCharset($this->dsn['charset'], $connection);
			if (PEAR::isError($result)) {
				return $result;
			}
		}

		$this->connection = $connection;
		$this->connected_dsn = $this->dsn;
		$this->connected_database_name = '';
		$this->opened_persistent = $this->options['persistent'];
		$this->dbsyntax = $this->dsn['dbsyntax'] ? $this->dsn['dbsyntax'] : $this->phptype;

		if ($this->database_name) {
			if ($this->database_name != $this->connected_database_name) {
				if (!@mysql_select_db($this->database_name, $connection)) {
					$err = $this->raiseError(null, null, null,
                        'Could not select the database: '.$this->database_name, __FUNCTION__);
					return $err;
				}
				$this->connected_database_name = $this->database_name;
			}
		}

		$this->supported['transactions'] = $this->options['use_transactions'];
		if ($this->options['default_table_type']) {
			switch (strtoupper($this->options['default_table_type'])) {
				case 'BLACKHOLE':
				case 'MEMORY':
				case 'ARCHIVE':
				case 'CSV':
				case 'HEAP':
				case 'ISAM':
				case 'MERGE':
				case 'MRG_ISAM':
				case 'ISAM':
				case 'MRG_MYISAM':
				case 'MYISAM':
					$this->supported['transactions'] = false;
					$this->warnings[] = $this->options['default_table_type'] .
                    ' is not a supported default table type';
					break;
			}
		}

		$this->supported['sub_selects'] = 'emulated';
		$this->supported['prepared_statements'] = 'emulated';
		$this->start_transaction = false;
		$this->varchar_max_length = 255;

		$server_info = $this->getServerVersion();
		if (is_array($server_info)) {
			if (!version_compare($server_info['major'].'.'.$server_info['minor'].'.'.$server_info['patch'], '4.1.0', '<')) {
				$this->supported['sub_selects'] = true;
				$this->supported['prepared_statements'] = true;
			}

			if (!version_compare($server_info['major'].'.'.$server_info['minor'].'.'.$server_info['patch'], '4.0.14', '<')
			|| !version_compare($server_info['major'].'.'.$server_info['minor'].'.'.$server_info['patch'], '4.1.1', '<')
			) {
				$this->supported['savepoints'] = true;
			}

			if (!version_compare($server_info['major'].'.'.$server_info['minor'].'.'.$server_info['patch'], '4.0.11', '<')) {
				$this->start_transaction = true;
			}

			if (!version_compare($server_info['major'].'.'.$server_info['minor'].'.'.$server_info['patch'], '5.0.3', '<')) {
				$this->varchar_max_length = 65532;
			}
		}

		return MDB2_OK;
	}
	// }}}
	// {{{ setCharset()

	/**
	 * Set the charset on the current connection
	 *
	 * @param string    charset
	 * @param resource  connection handle
	 *
	 * @return true on success, MDB2 Error Object on failure
	 */
	function setCharset($charset, $connection = null)
	{
		if (is_null($connection)) {
			$connection = $this->getConnection();
			if (PEAR::isError($connection)) {
				return $connection;
			}
		}

		$query = "SET character_set_client = '".mysql_real_escape_string($charset, $connection)."'";
		$result = @mysql_query($query, $connection);
		if (!$result) {
			return $this->raiseError(null, null, null,
                'Unable to set client charset: '.$charset, __FUNCTION__);
		}

		return MDB2_OK;
	}

	// }}}
	// {{{ disconnect()

	/**
	 * Log out and disconnect from the database.
	 *
	 * @param  boolean $force if the disconnect should be forced even if the
	 *                        connection is opened persistently
	 * @return mixed true on success, false if not connected and error
	 *                object on error
	 * @access public
	 */
	function disconnect($force = true)
	{
		if (is_resource($this->connection)) {
			if ($this->in_transaction) {
				$dsn = $this->dsn;
				$database_name = $this->database_name;
				$persistent = $this->options['persistent'];
				$this->dsn = $this->connected_dsn;
				$this->database_name = $this->connected_database_name;
				$this->options['persistent'] = $this->opened_persistent;
				$this->rollback();
				$this->dsn = $dsn;
				$this->database_name = $database_name;
				$this->options['persistent'] = $persistent;
			}

			if (!$this->opened_persistent || $force) {
				@mysql_close($this->connection);
			}
		}
		return parent::disconnect($force);
	}

	// }}}
	// {{{ _doQuery()

	/**
	 * Execute a query
	 * @param string $query  query
	 * @param boolean $is_manip  if the query is a manipulation query
	 * @param resource $connection
	 * @param string $database_name
	 * @return result or error object
	 * @access protected
	 */
	function &_doQuery($query, $is_manip = false, $connection = null, $database_name = null)
	{
		$this->last_query = $query;
		$result = $this->debug($query, 'query', array('is_manip' => $is_manip, 'when' => 'pre'));
		if ($result) {
			if (PEAR::isError($result)) {
				return $result;
			}
			$query = $result;
		}
		if ($this->options['disable_query']) {
			$result = $is_manip ? 0 : null;
			return $result;
		}

		if (is_null($connection)) {
			$connection = $this->getConnection();
			if (PEAR::isError($connection)) {
				return $connection;
			}
		}
		if (is_null($database_name)) {
			$database_name = $this->database_name;
		}

		if ($database_name) {
			if ($database_name != $this->connected_database_name) {
				if (!@mysql_select_db($database_name, $connection)) {
					$err = $this->raiseError(null, null, null,
                        'Could not select the database: '.$database_name, __FUNCTION__);
					return $err;
				}
				$this->connected_database_name = $database_name;
			}
		}

		$function = $this->options['result_buffering']
		? 'mysql_query' : 'mysql_unbuffered_query';
		$result = @$function($query, $connection);
		if (!$result) {
			$err =& $this->raiseError(null, null, null,
                'Could not execute statement', __FUNCTION__);
			return $err;
		}

		$this->debug($query, 'query', array('is_manip' => $is_manip, 'when' => 'post', 'result' => $result));
		return $result;
	}

	// }}}
	// {{{ _affectedRows()

	/**
	 * Returns the number of rows affected
	 *
	 * @param resource $result
	 * @param resource $connection
	 * @return mixed MDB2 Error Object or the number of rows affected
	 * @access private
	 */
	function _affectedRows($connection, $result = null)
	{
		if (is_null($connection)) {
			$connection = $this->getConnection();
			if (PEAR::isError($connection)) {
				return $connection;
			}
		}
		return @mysql_affected_rows($connection);
	}

	// }}}
	// {{{ _modifyQuery()

	/**
	 * Changes a query string for various DBMS specific reasons
	 *
	 * @param string $query  query to modify
	 * @param boolean $is_manip  if it is a DML query
	 * @param integer $limit  limit the number of rows
	 * @param integer $offset  start reading from given offset
	 * @return string modified query
	 * @access protected
	 */
	function _modifyQuery($query, $is_manip, $limit, $offset)
	{
		if ($this->options['portability'] & MDB2_PORTABILITY_DELETE_COUNT) {
			// "DELETE FROM table" gives 0 affected rows in MySQL.
			// This little hack lets you know how many rows were deleted.
			if (preg_match('/^\s*DELETE\s+FROM\s+(\S+)\s*$/i', $query)) {
				$query = preg_replace('/^\s*DELETE\s+FROM\s+(\S+)\s*$/',
                                      'DELETE FROM \1 WHERE 1=1', $query);
			}
		}
		if ($limit > 0
		&& !preg_match('/LIMIT\s*\d(\s*(,|OFFSET)\s*\d+)?/i', $query)
		) {
			$query = rtrim($query);
			if (substr($query, -1) == ';') {
				$query = substr($query, 0, -1);
			}
			if ($is_manip) {
				return $query . " LIMIT $limit";
			} else {
				return $query . " LIMIT $offset, $limit";
			}
		}
		return $query;
	}

	// }}}
	// {{{ getServerVersion()

	/**
	 * return version information about the server
	 *
	 * @param string     $native  determines if the raw version string should be returned
	 * @return mixed array/string with version information or MDB2 error object
	 * @access public
	 */
	function getServerVersion($native = false)
	{
		$connection = $this->getConnection();
		if (PEAR::isError($connection)) {
			return $connection;
		}
		if ($this->connected_server_info) {
			$server_info = $this->connected_server_info;
		} else {
			$server_info = @mysql_get_server_info($connection);
		}
		if (!$server_info) {
			return $this->raiseError(null, null, null,
                'Could not get server information', __FUNCTION__);
		}
		// cache server_info
		$this->connected_server_info = $server_info;
		if (!$native) {
			$tmp = explode('.', $server_info, 3);
			if (isset($tmp[2]) && strpos($tmp[2], '-')) {
				$tmp2 = explode('-', @$tmp[2], 2);
			} else {
				$tmp2[0] = isset($tmp[2]) ? $tmp[2] : null;
				$tmp2[1] = null;
			}
			$server_info = array(
                'major' => isset($tmp[0]) ? $tmp[0] : null,
                'minor' => isset($tmp[1]) ? $tmp[1] : null,
                'patch' => $tmp2[0],
                'extra' => $tmp2[1],
                'native' => $server_info,
			);
		}
		return $server_info;
	}

	// }}}
	// {{{ prepare()

	/**
	 * Prepares a query for multiple execution with execute().
	 * With some database backends, this is emulated.
	 * prepare() requires a generic query as string like
	 * 'INSERT INTO numbers VALUES(?,?)' or
	 * 'INSERT INTO numbers VALUES(:foo,:bar)'.
	 * The ? and :[a-zA-Z] and  are placeholders which can be set using
	 * bindParam() and the query can be send off using the execute() method.
	 *
	 * @param string $query the query to prepare
	 * @param mixed   $types  array that contains the types of the placeholders
	 * @param mixed   $result_types  array that contains the types of the columns in
	 *                        the result set or MDB2_PREPARE_RESULT, if set to
	 *                        MDB2_PREPARE_MANIP the query is handled as a manipulation query
	 * @param mixed   $lobs   key (field) value (parameter) pair for all lob placeholders
	 * @return mixed resource handle for the prepared query on success, a MDB2
	 *        error on failure
	 * @access public
	 * @see bindParam, execute
	 */
	function &prepare($query, $types = null, $result_types = null, $lobs = array())
	{
		if ($this->options['emulate_prepared']
		|| $this->supported['prepared_statements'] !== true
		) {
			$obj =& parent::prepare($query, $types, $result_types, $lobs);
			return $obj;
		}
		$is_manip = ($result_types === MDB2_PREPARE_MANIP);
		$offset = $this->offset;
		$limit = $this->limit;
		$this->offset = $this->limit = 0;
		$query = $this->_modifyQuery($query, $is_manip, $limit, $offset);
		$result = $this->debug($query, __FUNCTION__, array('is_manip' => $is_manip, 'when' => 'pre'));
		if ($result) {
			if (PEAR::isError($result)) {
				return $result;
			}
			$query = $result;
		}
		$placeholder_type_guess = $placeholder_type = null;
		$question = '?';
		$colon = ':';
		$positions = array();
		$position = 0;
		while ($position < strlen($query)) {
			$q_position = strpos($query, $question, $position);
			$c_position = strpos($query, $colon, $position);
			if ($q_position && $c_position) {
				$p_position = min($q_position, $c_position);
			} elseif ($q_position) {
				$p_position = $q_position;
			} elseif ($c_position) {
				$p_position = $c_position;
			} else {
				break;
			}
			if (is_null($placeholder_type)) {
				$placeholder_type_guess = $query[$p_position];
			}

			$new_pos = $this->_skipDelimitedStrings($query, $position, $p_position);
			if (PEAR::isError($new_pos)) {
				return $new_pos;
			}
			if ($new_pos != $position) {
				$position = $new_pos;
				continue; //evaluate again starting from the new position
			}

			if ($query[$position] == $placeholder_type_guess) {
				if (is_null($placeholder_type)) {
					$placeholder_type = $query[$p_position];
					$question = $colon = $placeholder_type;
				}
				if ($placeholder_type == ':') {
					$parameter = preg_replace('/^.{'.($position+1).'}([a-z0-9_]+).*$/si', '\\1', $query);
					if ($parameter === '') {
						$err =& $this->raiseError(MDB2_ERROR_SYNTAX, null, null,
                            'named parameter with an empty name', __FUNCTION__);
						return $err;
					}
					$positions[$p_position] = $parameter;
					$query = substr_replace($query, '?', $position, strlen($parameter)+1);
				} else {
					$positions[$p_position] = count($positions);
				}
				$position = $p_position + 1;
			} else {
				$position = $p_position;
			}
		}
		$connection = $this->getConnection();
		if (PEAR::isError($connection)) {
			return $connection;
		}
		$statement_name = sprintf($this->options['statement_format'], $this->phptype, md5(time() + rand()));
		$query = "PREPARE $statement_name FROM ".$this->quote($query, 'text');
		$statement =& $this->_doQuery($query, true, $connection);
		if (PEAR::isError($statement)) {
			return $statement;
		}

		$class_name = 'MDB2_Statement_'.$this->phptype;
		$obj =& new $class_name($this, $statement_name, $positions, $query, $types, $result_types, $is_manip, $limit, $offset);
		$this->debug($query, __FUNCTION__, array('is_manip' => $is_manip, 'when' => 'post', 'result' => $obj));
		return $obj;
	}

	// }}}
	// {{{ replace()

	/**
	 * Execute a SQL REPLACE query. A REPLACE query is identical to a INSERT
	 * query, except that if there is already a row in the table with the same
	 * key field values, the REPLACE query just updates its values instead of
	 * inserting a new row.
	 *
	 * The REPLACE type of query does not make part of the SQL standards. Since
	 * practically only MySQL implements it natively, this type of query is
	 * emulated through this method for other DBMS using standard types of
	 * queries inside a transaction to assure the atomicity of the operation.
	 *
	 * @access public
	 *
	 * @param string $table name of the table on which the REPLACE query will
	 *  be executed.
	 * @param array $fields associative array that describes the fields and the
	 *  values that will be inserted or updated in the specified table. The
	 *  indexes of the array are the names of all the fields of the table. The
	 *  values of the array are also associative arrays that describe the
	 *  values and other properties of the table fields.
	 *
	 *  Here follows a list of field properties that need to be specified:
	 *
	 *    value:
	 *          Value to be assigned to the specified field. This value may be
	 *          of specified in database independent type format as this
	 *          function can perform the necessary datatype conversions.
	 *
	 *    Default:
	 *          this property is required unless the Null property
	 *          is set to 1.
	 *
	 *    type
	 *          Name of the type of the field. Currently, all types Metabase
	 *          are supported except for clob and blob.
	 *
	 *    Default: no type conversion
	 *
	 *    null
	 *          Boolean property that indicates that the value for this field
	 *          should be set to null.
	 *
	 *          The default value for fields missing in INSERT queries may be
	 *          specified the definition of a table. Often, the default value
	 *          is already null, but since the REPLACE may be emulated using
	 *          an UPDATE query, make sure that all fields of the table are
	 *          listed in this function argument array.
	 *
	 *    Default: 0
	 *
	 *    key
	 *          Boolean property that indicates that this field should be
	 *          handled as a primary key or at least as part of the compound
	 *          unique index of the table that will determine the row that will
	 *          updated if it exists or inserted a new row otherwise.
	 *
	 *          This function will fail if no key field is specified or if the
	 *          value of a key field is set to null because fields that are
	 *          part of unique index they may not be null.
	 *
	 *    Default: 0
	 *
	 * @return mixed MDB2_OK on success, a MDB2 error on failure
	 */
	function replace($table, $fields)
	{
		$count = count($fields);
		$query = $values = '';
		$keys = $colnum = 0;
		for (reset($fields); $colnum < $count; next($fields), $colnum++) {
			$name = key($fields);
			if ($colnum > 0) {
				$query .= ',';
				$values.= ',';
			}
			$query.= $name;
			if (isset($fields[$name]['null']) && $fields[$name]['null']) {
				$value = 'NULL';
			} else {
				$type = isset($fields[$name]['type']) ? $fields[$name]['type'] : null;
				$value = $this->quote($fields[$name]['value'], $type);
			}
			$values.= $value;
			if (isset($fields[$name]['key']) && $fields[$name]['key']) {
				if ($value === 'NULL') {
					return $this->raiseError(MDB2_ERROR_CANNOT_REPLACE, null, null,
                        'key value '.$name.' may not be NULL', __FUNCTION__);
				}
				$keys++;
			}
		}
		if ($keys == 0) {
			return $this->raiseError(MDB2_ERROR_CANNOT_REPLACE, null, null,
                'not specified which fields are keys', __FUNCTION__);
		}

		$connection = $this->getConnection();
		if (PEAR::isError($connection)) {
			return $connection;
		}

		$query = "REPLACE INTO $table ($query) VALUES ($values)";
		$result =& $this->_doQuery($query, true, $connection);
		if (PEAR::isError($result)) {
			return $result;
		}
		return $this->_affectedRows($connection, $result);
	}

	// }}}
	// {{{ nextID()

	/**
	 * Returns the next free id of a sequence
	 *
	 * @param string $seq_name name of the sequence
	 * @param boolean $ondemand when true the sequence is
	 *                          automatic created, if it
	 *                          not exists
	 *
	 * @return mixed MDB2 Error Object or id
	 * @access public
	 */
	function nextID($seq_name, $ondemand = true)
	{
		$sequence_name = $this->quoteIdentifier($this->getSequenceName($seq_name), true);
		$seqcol_name = $this->quoteIdentifier($this->options['seqcol_name'], true);
		$query = "INSERT INTO $sequence_name ($seqcol_name) VALUES (NULL)";
		$this->expectError(MDB2_ERROR_NOSUCHTABLE);
		$result =& $this->_doQuery($query, true);
		$this->popExpect();
		if (PEAR::isError($result)) {
			if ($ondemand && $result->getCode() == MDB2_ERROR_NOSUCHTABLE) {
				$this->loadModule('Manager', null, true);
				$result = $this->manager->createSequence($seq_name);
				if (PEAR::isError($result)) {
					return $this->raiseError($result, null, null,
                        'on demand sequence '.$seq_name.' could not be created', __FUNCTION__);
				} else {
					return $this->nextID($seq_name, false);
				}
			}
			return $result;
		}
		$value = $this->lastInsertID();
		if (is_numeric($value)) {
			$query = "DELETE FROM $sequence_name WHERE $seqcol_name < $value";
			$result =& $this->_doQuery($query, true);
			if (PEAR::isError($result)) {
				$this->warnings[] = 'nextID: could not delete previous sequence table values from '.$seq_name;
			}
		}
		return $value;
	}

	// }}}
	// {{{ lastInsertID()

	/**
	 * Returns the autoincrement ID if supported or $id or fetches the current
	 * ID in a sequence called: $table.(empty($field) ? '' : '_'.$field)
	 *
	 * @param string $table name of the table into which a new row was inserted
	 * @param string $field name of the field into which a new row was inserted
	 * @return mixed MDB2 Error Object or id
	 * @access public
	 */
	function lastInsertID($table = null, $field = null)
	{
		// not using mysql_insert_id() due to http://pear.php.net/bugs/bug.php?id=8051
		return $this->queryOne('SELECT LAST_INSERT_ID()', 'integer');
	}

	// }}}
	// {{{ currID()

	/**
	 * Returns the current id of a sequence
	 *
	 * @param string $seq_name name of the sequence
	 * @return mixed MDB2 Error Object or id
	 * @access public
	 */
	function currID($seq_name)
	{
		$sequence_name = $this->quoteIdentifier($this->getSequenceName($seq_name), true);
		$seqcol_name = $this->quoteIdentifier($this->options['seqcol_name'], true);
		$query = "SELECT MAX($seqcol_name) FROM $sequence_name";
		return $this->queryOne($query, 'integer');
	}
}

/**
 * MDB2 MySQL result driver
 *
 * @package MDB2
 * @category Database
 * @author  Lukas Smith <smith@pooteeweet.org>
 */
class MDB2_Result_mysql extends MDB2_Result_Common
{
	// }}}
	// {{{ fetchRow()

	/**
	 * Fetch a row and insert the data into an existing array.
	 *
	 * @param int       $fetchmode  how the array data should be indexed
	 * @param int    $rownum    number of the row where the data can be found
	 * @return int data array on success, a MDB2 error on failure
	 * @access public
	 */
	function &fetchRow($fetchmode = MDB2_FETCHMODE_DEFAULT, $rownum = null)
	{
		if (!is_null($rownum)) {
			$seek = $this->seek($rownum);
			if (PEAR::isError($seek)) {
				return $seek;
			}
		}
		if ($fetchmode == MDB2_FETCHMODE_DEFAULT) {
			$fetchmode = $this->db->fetchmode;
		}
		if ($fetchmode & MDB2_FETCHMODE_ASSOC) {
			$row = @mysql_fetch_assoc($this->result);
			if (is_array($row)
			&& $this->db->options['portability'] & MDB2_PORTABILITY_FIX_CASE
			) {
				$row = array_change_key_case($row, $this->db->options['field_case']);
			}
		} else {
			$row = @mysql_fetch_row($this->result);
		}

		if (!$row) {
			if ($this->result === false) {
				$err =& $this->db->raiseError(MDB2_ERROR_NEED_MORE_DATA, null, null,
                    'resultset has already been freed', __FUNCTION__);
				return $err;
			}
			$null = null;
			return $null;
		}
		$mode = $this->db->options['portability'] & MDB2_PORTABILITY_EMPTY_TO_NULL;
		if ($mode) {
			$this->db->_fixResultArrayValues($row, $mode);
		}
		if (!empty($this->types)) {
			$row = $this->db->datatype->convertResultRow($this->types, $row, false);
		}
		if (!empty($this->values)) {
			$this->_assignBindColumns($row);
		}
		if ($fetchmode === MDB2_FETCHMODE_OBJECT) {
			$object_class = $this->db->options['fetch_class'];
			if ($object_class == 'stdClass') {
				$row = (object) $row;
			} else {
				$row = &new $object_class($row);
			}
		}
		++$this->rownum;
		return $row;
	}

	// }}}
	// {{{ _getColumnNames()

	/**
	 * Retrieve the names of columns returned by the DBMS in a query result.
	 *
	 * @return  mixed   Array variable that holds the names of columns as keys
	 *                  or an MDB2 error on failure.
	 *                  Some DBMS may not return any columns when the result set
	 *                  does not contain any rows.
	 * @access private
	 */
	function _getColumnNames()
	{
		$columns = array();
		$numcols = $this->numCols();
		if (PEAR::isError($numcols)) {
			return $numcols;
		}
		for ($column = 0; $column < $numcols; $column++) {
			$column_name = @mysql_field_name($this->result, $column);
			$columns[$column_name] = $column;
		}
		if ($this->db->options['portability'] & MDB2_PORTABILITY_FIX_CASE) {
			$columns = array_change_key_case($columns, $this->db->options['field_case']);
		}
		return $columns;
	}

	// }}}
	// {{{ numCols()

	/**
	 * Count the number of columns returned by the DBMS in a query result.
	 *
	 * @return mixed integer value with the number of columns, a MDB2 error
	 *                       on failure
	 * @access public
	 */
	function numCols()
	{
		$cols = @mysql_num_fields($this->result);
		if (is_null($cols)) {
			if ($this->result === false) {
				return $this->db->raiseError(MDB2_ERROR_NEED_MORE_DATA, null, null,
                    'resultset has already been freed', __FUNCTION__);
			} elseif (is_null($this->result)) {
				return count($this->types);
			}
			return $this->db->raiseError(null, null, null,
                'Could not get column count', __FUNCTION__);
		}
		return $cols;
	}

	// }}}
	// {{{ free()

	/**
	 * Free the internal resources associated with result.
	 *
	 * @return boolean true on success, false if result is invalid
	 * @access public
	 */
	function free()
	{
		if (is_resource($this->result) && $this->db->connection) {
			$free = @mysql_free_result($this->result);
			if ($free === false) {
				return $this->db->raiseError(null, null, null,
                    'Could not free result', __FUNCTION__);
			}
		}
		$this->result = false;
		return MDB2_OK;
	}
}

/**
 * MDB2 MySQL buffered result driver
 *
 * @package MDB2
 * @category Database
 * @author  Lukas Smith <smith@pooteeweet.org>
 */
class MDB2_BufferedResult_mysql extends MDB2_Result_mysql
{
	// }}}
	// {{{ seek()

	/**
	 * Seek to a specific row in a result set
	 *
	 * @param int    $rownum    number of the row where the data can be found
	 * @return mixed MDB2_OK on success, a MDB2 error on failure
	 * @access public
	 */
	function seek($rownum = 0)
	{
		if ($this->rownum != ($rownum - 1) && !@mysql_data_seek($this->result, $rownum)) {
			if ($this->result === false) {
				return $this->db->raiseError(MDB2_ERROR_NEED_MORE_DATA, null, null,
                    'resultset has already been freed', __FUNCTION__);
			} elseif (is_null($this->result)) {
				return MDB2_OK;
			}
			return $this->db->raiseError(MDB2_ERROR_INVALID, null, null,
                'tried to seek to an invalid row number ('.$rownum.')', __FUNCTION__);
		}
		$this->rownum = $rownum - 1;
		return MDB2_OK;
	}

	// }}}
	// {{{ valid()

	/**
	 * Check if the end of the result set has been reached
	 *
	 * @return mixed true or false on sucess, a MDB2 error on failure
	 * @access public
	 */
	function valid()
	{
		$numrows = $this->numRows();
		if (PEAR::isError($numrows)) {
			return $numrows;
		}
		return $this->rownum < ($numrows - 1);
	}

	// }}}
	// {{{ numRows()

	/**
	 * Returns the number of rows in a result object
	 *
	 * @return mixed MDB2 Error Object or the number of rows
	 * @access public
	 */
	function numRows()
	{
		$rows = @mysql_num_rows($this->result);
		if (is_null($rows)) {
			if ($this->result === false) {
				return $this->db->raiseError(MDB2_ERROR_NEED_MORE_DATA, null, null,
                    'resultset has already been freed', __FUNCTION__);
			} elseif (is_null($this->result)) {
				return 0;
			}
			return $this->db->raiseError(null, null, null,
                'Could not get row count', __FUNCTION__);
		}
		return $rows;
	}
}

/**
 * MDB2 MySQL statement driver
 *
 * @package MDB2
 * @category Database
 * @author  Lukas Smith <smith@pooteeweet.org>
 */
class MDB2_Statement_mysql extends MDB2_Statement_Common
{
	// {{{ _execute()

	/**
	 * Execute a prepared query statement helper method.
	 *
	 * @param mixed $result_class string which specifies which result class to use
	 * @param mixed $result_wrap_class string which specifies which class to wrap results in
	 * @return mixed a result handle or MDB2_OK on success, a MDB2 error on failure
	 * @access private
	 */
	function &_execute($result_class = true, $result_wrap_class = false)
	{
		if (is_null($this->statement)) {
			$result =& parent::_execute($result_class, $result_wrap_class);
			return $result;
		}
		$this->db->last_query = $this->query;
		$this->db->debug($this->query, 'execute', array('is_manip' => $this->is_manip, 'when' => 'pre', 'parameters' => $this->values));
		if ($this->db->getOption('disable_query')) {
			$result = $this->is_manip ? 0 : null;
			return $result;
		}

		$connection = $this->db->getConnection();
		if (PEAR::isError($connection)) {
			return $connection;
		}

		$query = 'EXECUTE '.$this->statement;
		if (!empty($this->positions)) {
			$parameters = array();
			foreach ($this->positions as $parameter) {
				if (!array_key_exists($parameter, $this->values)) {
					return $this->db->raiseError(MDB2_ERROR_NOT_FOUND, null, null,
                        'Unable to bind to missing placeholder: '.$parameter, __FUNCTION__);
				}
				$value = $this->values[$parameter];
				$type = array_key_exists($parameter, $this->types) ? $this->types[$parameter] : null;
				if (is_resource($value) || $type == 'clob' || $type == 'blob') {
					if (!is_resource($value) && preg_match('/^(\w+:\/\/)(.*)$/', $value, $match)) {
						if ($match[1] == 'file://') {
							$value = $match[2];
						}
						$value = @fopen($value, 'r');
						$close = true;
					}
					if (is_resource($value)) {
						$data = '';
						while (!@feof($value)) {
							$data.= @fread($value, $this->db->options['lob_buffer_length']);
						}
						if ($close) {
							@fclose($value);
						}
						$value = $data;
					}
				}
				$param_query = 'SET @'.$parameter.' = '.$this->db->quote($value, $type);
				$result = $this->db->_doQuery($param_query, true, $connection);
				if (PEAR::isError($result)) {
					return $result;
				}
			}
			$query.= ' USING @'.implode(', @', array_values($this->positions));
		}

		$result = $this->db->_doQuery($query, $this->is_manip, $connection);
		if (PEAR::isError($result)) {
			return $result;
		}

		if ($this->is_manip) {
			$affected_rows = $this->db->_affectedRows($connection, $result);
			return $affected_rows;
		}

		$result =& $this->db->_wrapResult($result, $this->result_types,
		$result_class, $result_wrap_class, $this->limit, $this->offset);
		$this->db->debug($this->query, 'execute', array('is_manip' => $this->is_manip, 'when' => 'post', 'result' => $result));
		return $result;
	}

	// }}}
	// {{{ free()

	/**
	 * Release resources allocated for the specified prepared query.
	 *
	 * @return mixed MDB2_OK on success, a MDB2 error on failure
	 * @access public
	 */
	function free()
	{
		if (is_null($this->positions)) {
			return $this->db->raiseError(MDB2_ERROR, null, null,
                'Prepared statement has already been freed', __FUNCTION__);
		}
		$result = MDB2_OK;

		if (!is_null($this->statement)) {
			$connection = $this->db->getConnection();
			if (PEAR::isError($connection)) {
				return $connection;
			}
			$query = 'DEALLOCATE PREPARE '.$this->statement;
			$result = $this->db->_doQuery($query, true, $connection);
		}

		parent::free();
		return $result;
	}
}
?>